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  1. #1
    fly like a beagle
    Reputation: GaHeckler's Avatar
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    med cage derailleur

    Will a med cage sram work with a 34 tooth cassette? (44 ,34, 24 front rings)
    Really?This things got Brakes?

  2. #2
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    yes but ...

    you'll probably not have enough spare chain in your der. to enable all gear choices.

    I'm running a med cage der (Sram X9) with a 11-34 / 44-32-22 combination and it works but I don't cross chain or 11-22.
    Also you have mentioned if your bike is a FS or HT. FS bikes usualy like a bit more chain (so long cage) because of the chain tightening when you compress the rear shock.

    Go to the Sram web site they have a formula to calculate what each der (small, med or long) cab take. Or do a search in this forum, it's there.

  3. #3
    Chrome Toaster
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    It can work but you need to factor in a few possibilities. You can leave the chain long enough to use all possible gear combo's plus any extra you might need to compensate for growing chainlstays on some FS bikes. If you do the chain will end up limp on the granny and some small gears (no reason to go there though). The other option is to trim the chain enough so its never limp in any gear but you need to be VERY careful about no acidentally going to the big ring an bigger cogs as well as making sure the suspension action will not tear the derailleur of if you ride too big combinations.

  4. #4
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    Go Long Cage

    Quote Originally Posted by GaHeckler
    Will a med cage sram work with a 34 tooth cassette? (44 ,34, 24 front rings)
    I had the same question this morning, so I called SRAM and talked to their tech support. My setup is standard 11-34 rear and 22-32-44 front on a FS bike. They emphatically said long cage. Anything else will break, unless you are very careful about which gear combinations you select. My opinion is that for the very small hit on weight (and bling factor - med cage is carbon and long cage is alloy) I want to be able to select any gear combination.

    I'm going long cage.

  5. #5
    Just Ride
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    Quote Originally Posted by GaHeckler
    Will a med cage sram work with a 34 tooth cassette? (44 ,34, 24 front rings)
    Here's how you caculate it;
    Big Ring - Small Ring = ?
    Big Cog - Small Cog= ?
    Add up the results and that tells you which derailleur you need.
    In your case:
    44-24= 20 let say your cassette gear ratio is 11-34. 34-11= 23. Then you add up the results which gives you 20+23= 43. A medium cage derailleur has a total capacity of 37
    (Sram der.) and 33 (Shimano der.) Since 43 is greater than 33 and 37, you need a long cage.
    Last edited by whitelizard; 11-09-2005 at 10:21 PM.

  6. #6
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    I can see how having a chain that's too short can cause damage if you shift into a big/big combo, but how will having too much chain slack in a small/small combo be dangerous? The chain is probably more likely to fall off the cogs or chainrings, but that's all I can think of.

    FWIW - I've used a medium cage derailluer with 32 and 34 tooth cassette and triple chainrings up front for years and never had any issues. I set my chain length by using the "wrap the chain around the big ring/big cog and add a link" method. There is slack in the small/small combos, but those combos are never (intentionally) used, and when they have been unintentionally used, it's never cause a problem.

    I agree that long cages make more sense on triple ring bikes, but I'm just trying to understand how a medium cage would cause a problem.

  7. #7
    Chrome Toaster
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    You're right, having the chain go limp on the small-small is not likely to normaly cause any damage unlike having it too short. The worst might be the chain falls off to the BB shell or something.

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